Most of the strategic elements documented by Mission 2016 are critical due to their usage in certain technologies, or because of their unique physical or electrochemical properties. Phosphorus is irreplaceable in organic life. It's a central atom in the backbone of DNA, shared by every living creature on earth, and it is used by human cells in adenosine triphosphate (ATP) as the primary means of energy storage. In the natural phosphorus cycle, mineral phosphate is freed from rock by erosion, makes its way into soil, and is absorbed by plants. Plants are then consumed by humans and animals, and phosphorus is re-introduced to the environment through waste and decomposition. For thousands of years, agriculture used only organic waste and remains to fertilize crops. The production, consumption and disposal of food formed a closed loop, and net phosphorus in the cycle remained relatively constant. Today, however, large-scale agriculture in the wake of the green revolution demands focused, synthetic fertilizers to provide the nutrients for higher-yield crops. Phosphorus and nitrogen are mined from the ground and removed from the air, such that the entire cycle is thrown out of balance.

Current Production and Prospective Deposits

Phosphorus is mined primarily as phosphate rock, a fairly common rock found worldwide. It takes about 1 ton of phosphate to produce 130 tons of grain, although this figure is highly variable depending on soil conditions, farm history, crop type, and fertilizing efficiency (Vaccari, 2009). Approximately 191 Mt (megatons = millions of tons) of phosphate rock were mined last year, and the USGS estimates global phosphate reserves at 71,000 Mt (Jasinski, 2012). In 2010, the USGS defined their estimates of "reserves" to include only minerals they considered economically viable with current technology, pegging the global total at just 16,000 Mt (Jasinski, 2010). In 2011, they changed their method of calculating reserves to be more encompassing, and continued the practice in 2012. Since 2010, deposits of at least 1 Gt have been discovered in Morocco, the Sahara, Algeria, and Iraq, but with a dearth of data on the viability of these deposits, it's safer to assume the 2010 estimate is still accurate. If so, at current production levels the world will exhaust these reserves in fewer than 80 years.

"Peak" production refers to the point in time at which maximum global production is reached, and after which it will only decline. This concept is applicable to many finite natural resources extracted by humans, and has been famously applied to oil in recent years (Ralston, 2008; Carlson, 2012; Michel, 2012). Proponents of the theory argue that, due to the finite nature of resources and the increasing nature of demand, the important prediction is not when the world will run out of supply completely, but rather when it will run out of high-grade, easily-acquirable phosphate rock (Schroeder et al., 2010). This framework lends even more more credence to the conservative 16,000 Mt estimate of the world's reserves, as they may very well be the only readily accessible materials left to mine. Although there will undoubtedly be more phosphate discoveries after these are depleted, they will require progressively more effort and expense to extract and refine, and production will already be on an inexorable path of decline.

According to peak theory, at current production rates, the world's phosphate production will reach its maximum before 2040, and enter a long, slow decline. However, the world's consumption levels will continue to rise, creating an ever-widening supply-demand gap.

The primary use of phosphorus is in fertilizer for food. Naturally, phosphorus demand is dependent on food production, and by extension population growth, which is currently about 1.2% per year (World Bank, from Google, 2012). In addition, China, India, and other developing countries have emerging middle classes that will demand more meat, causing fertilizer demand to grow even more (as livestock are less phosphorus-efficient than plants) (Vaccari, 2009). Although the US has nearly doubled its phosphorous-to-crop-yield ratio in crucial crops like corn since it reached peak use in the 1980s (The Fertilizer Institute, n.d.), China is a very inefficient consumer of fertilizer: a recent China Agriculture University study found that northern Chinese farmers use about 525 pounds of fertilizer per acre, of which 200 pounds is wasted into the environment. This is six times more fertilizer and 23 times more waste than the average American farmer in the midwest uses and produces (Shwartz, 2009). These phenomena of growth and overuse, coinciding with peak production, will drive prices drastically higher and force a number of changes in the world's food production and consumption. The potential for catastrophic food shortages and global famine looms without significant systemic changes.

Geopolitical Factors in Future Production

The non-trivial issues of limited supply for accelerating demand are further complicated by the fact that phosphorus is geologically concentrated only in certain areas. Although globally, elemental phosphorus is relatively abundant, high-grade phosphate rock exists in just a few areas. They are even fewer and more concentrated than oil deposits (Vaccari, 2009). There will undoubtedly be new reserves found in the future, but most recent discoveries have occurred in just a few places, mostly Morocco and the western Sahara. In fact, more than 70% of documented phosphate on earth is located in Morocco. (Jasinski, 2012). Other recent discoveries have been in Iraq (which is the world's second largest reserve holder), Algeria (which is fourth), Syria (fifth), and North Carolina [the US is ninth, although North Carolina's reserves are mostly unavailable as they underlie sensitive ecosystems (Vaccari, 2009)]. Currently, of the top seven reserve holders in the world, Morocco and Algeria are politically stable relative to other nation-states in their region. However, Iraq, Syria, and Jordan, with the sixth largest reserves, are all unstable areas prone to conflict. Rounding out the top seven are China, which is a net importer, and South Africa, which produces little but has potential (Jasinski, 2012). While it is still unclear how many of these deposits will ultimately be viable, phosphorus-fueled conflicts analogous to the oil conflicts of the 1990s and 2000s could be a major problem in years to come.